No practical noninvasive antemortem test exists to detect cervid, human, or any, prion disease. Blood- borne transmission of prions from asymptomatic human variant Creutzfeldt Jakob Disease (vCJD)-infected humans has occurred(12,14-16). Chronic wasting disease (CWD) is an emergent rapidly spreading disease in cervids(27,28,37-40) with uncertain zoonotic potential(3-8). An estimated one in 36 Americans hunt deer and/or elk, resulting in an estimated 7,000-15,000 CWD-infected cervids consumed annually in the USA (increasing 20%/yr)(2). As hunting is a roughly $26 billion (per annum) industry(1), CWD represents an enormous potential health and economic threat. The commonalities among vCJD and cervid CWD, including the presence of hematogenous infectivity(34,47), are remarkable. Antemortem detection and surveillance of human, and animal, prion disease has been hindered by the combination of low prion concentrations and abundant assay inhibitors in blood and other accessible biological samples. We have developed simple, rapid, specific and highly sensitive in vitro assays to detect blood-borne prions(9-11). In this competing renewal we will quantitate the temporal distribution and specific blood cell phenotypes critical to prionemia in serially-collected human and cervid blood samples. The translational impact of the results of these studies will: a) improve human blood transfusion safety, b) provide a better means to assess and monitor developing prion therapeutics, c) largely eliminate the risks of human consumption of cervid prions, d) provide greater understanding of the prevalence and consequences of CWD to the cervid hunting and agriculture industries, and e) elucidate our understanding of prionemia in disease pathogenesis. Thereby, this research will have immediate impacts in both human and animal health.